Is it necessary to thoroughly pre-validate a product before launching?

Pre-validation means credible tests to verify that there's demand to pay for your product or service, e.g., launching a fake beta, signing up customers to a waiting list, taking payment info for pre-sales, etc.

I am a developer and I want to launch several micro products to make additional money on the side. I am finding pre-validation extremely draining and not fun. I don't know how to reach people - as soon as I start talking about building they are not interested or think I am trying to sell them something. There is also a lot of time to wait on responses, whereas when developing a product I can always do something.

I am a developer and I like building products. When I listen on IndieHackers, I think there is about a 50/50 split between hackers who took the time to validate and pre-sell their ideas and hackers who just went ahead and built it. For those who did pre-validate, the number who went beyond asking a few potential customers if what they were building sounded interesting seems to be small.

What did you do? Did you just build something that seemed important to you (maybe in stages/iteratively, but did just build) or did you spend a lot of time/money/effort finding out if someone wants it before building it?